Rhinosinusitis is a common paranasal sinus condition that is generally understood as encompassing sinusitis and/or rhinitis. Typically, rhinosinusitis is characterized by major symptoms such as nasal discharge, nasal obstruction, facial congestion, facial pain/pressure, loss of smell, and fever, and minor symptoms such as headache, ear pain/pressure, halitosis, dental pain, cough, and fatigue.
Allergic rhinitis is associated with a group of symptoms affecting the nose that occurs when an individual with the condition breaths in an allergen, such as dust, mold, or animal dander. Allergens cause the release of histamine, which usually causes sneezing, itchy and watery eyes, runny nose, swelling and inflammation of the nasal passages, an increase in mucus production, and for some individuals, hives or other rashes. Allergic rhinitis due to pollen is commonly known as hay fever.
Current treatments for these and other nasal conditions, as well as certain otic and throat conditions, are primarily pharmaceutical. Drugs in pill form are widely available and easy to take, but can have several drawbacks. An orally administered drug may require considerable time to work through the body to become effective, and may have negative side effects that can impact the daily life of the patient. Also, the drug may need to be taken frequently for continued symptom relief. Nasal, otic, and throat topical drug delivery represents an attractive alternative approach for the treatment of local nasal, otic, and throat diseases. However, current technologies for local drug delivery of drugs in either liquid or powder form, and by spray or direct application, can be limited by poor patient compliance when repeated doses are required, or poor efficacy due to challenges in delivering a drug to more distal sinus and ear anatomies.
Another challenge with topical drug delivery is presented when the nasal condition involves treatment of mucosal tissue. Most mucosal epithelial tissues are covered with a glycoprotein rich mucus layer. This mucus layer is a dynamic layer that generally works to clear contaminants from the respiratory system. It typically has a transit and turnover time of approximately 15-20 minutes. A locally delivered drug must pass through this mucus layer and be taken up by the mucosal epithelium before it is moved away from the target tissue site.
Accordingly, for certain nasal, otic, and throat conditions, it may be desirable to treat distal anatomies by distributing high concentrations of drugs with reduced dosing frequency evenly across treated sites and in the absence of a permanent implant for applications where mechanical support is not necessary. Regarding nasal conditions, it may be useful to have treatments that can both deliver drugs and dilate target sites such as the paranasal sinuses and/or deliver drugs to multiple sites with a single device. When mucosal tissues are affected, it would be desirable to have topical treatments where drugs can be delivered and taken up by tissue before they are cleared from the site by mucociliary flow.